Climate change directly affects food security and nutrition. It undermines current efforts to protect the lives and livelihoods and end the suffering of the over 1 billion food insecure people and will increase the risk of hunger and malnutrition by an unprecedented scale within the next decades. Undernutrition is already the single largest contributor to the global burden of disease, killing 3.5 million people every year, almost all of them children in developing countries. Unless urgent action is taken, it will not be possible to ensure the food security of a growing world population under a changing climate. This paper highlights some of the projected impacts of climate change on food security and summarizes the responses called for by several of the largest humanitarian and development organizations involved in the fight against hunger.